Due to EPA regulations, The Factory fuel setting makes the RZR Rich on Bottom and Lean on Top. The DFR Controller comes with a Standard Setting to increase power through the entire power band; it will also have the ability to be tuned for aftermarket exhaust, and will come set up with a calibration for the DragonFire Performance Exhaust. There is also and O2 Sensor that can be purchased that will allow the computer to adjust with climate and elevation changes. Make you RZR the fastest RZR in the dirt. DragonFire Racing G3 Fuel Controller the right choice for RZR performance. Aftermarket Controller with increased RPM Increased RPM only helps a vehicle if it is clutched to do so, and if it creates additional HP beyond the current RPM. If your vehicles final drive is 5850 RMP then additional RMP will only help in an overdrive situation. This will happen on concrete only. The stock motor revs to 6500 RPM. In the sand the vehicle does not have the HP or TQ to pull any additional RPM, nor is a clutch designed to pull any increased RPM. The second concern with RMP exceeding 6500 is that the Crank starts orbiting and that the motor will self destruct. There is nothing to hold the RZR Crank in place. 6500 RMP is the Happy spot for the RZR. Outside of being the fastest RZR on concrete there is no additional benefit. We have seen Cranks and push rods destroyed while increasing RPM. DFR Stage 2 Clutch Kit This is necessary when adding the additional HP that comes with our RZR Controller, intake and DFR RZR Full Exhaust. You can not increase power with out proper clutching. We increase the low end Drive squeeze, the RZR gains tremendous low and mid acceleration. 5850 is final Drive RPM, with 26 inch tires the RZR will do 62 MPH Removing RZR Factory Spacer: DO NOT REMOVE: By removing the OE spacer you will create extra overdrive and but at the same time you will compromise your vehicles back shifting. The vehicle will be slower to come out of overdrive, and will constantly pulling too tall of a gear. The second major concern is the belt now rides two low in the secondary. The sheeves that belt rides in have a machined taper. At a certain point, the point where the stock spacer limits the sheeve, there is no more taper, the belt will become stuck below the taper causing damage to the clutch and belt, and potential the driver if it bound the motor. Many people have found that this happens while going down hill at high speed. DFR RZR Belt Rated to 100 HP Heat and HP compromise belts. The DFR RZR belt is designed for both and will allow for heavy load as well as horse power.

More Info: http://www.dragonfireracing.com/polarisrangerrzrperformancecontroller.aspx